res1: Map = Map("foo", 1, "bar", 2)
res2: Mapping = new {
  ["foo"] = 1
  ["bar"] = 2
}
res3: Mapping = new {
  ["childMap"] = new Mapping {
    ["childFoo"] = 3
  }
}
res4: Mapping = new {
  [Map("foo", 1)] = new Mapping {
    ["bar"] = 2
  }
}
